Myotonic dystrophy (DM) and facioscapulohumeral muscular dystrophy (FSHD) are inherited disorders characterized by progressive muscle weakness and loss of muscle tissue. The purpose of this registry is to connect people with DM or FSHD with researchers studying these diseases. The registry will offer individuals with DM and FSHD an opportunity to participate in research that focuses of their diseases. The registry will also help scientists to accomplish research on DM and FSHD and to distribute their findings to patients and care providers. The National Registry of DM and FSHD Patients and Family Members was developed to create a link between patients and scientists in order to promote research on these rare illnesses. The Registry is sponsored by the National Institutes of Health.